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  <title>Open connection to system logger</title>

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</div><hr /><div id="function.openlog" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">openlog</h1>
  <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">openlog</span> &mdash; <span class="dc-title">Open connection to system logger</span></p>

 </div>
 
 <div class="refsect1 description" id="refsect1-function.openlog-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="type">bool</span> <span class="methodname"><strong>openlog</strong></span>
    ( <span class="methodparam"><span class="type">string</span> <code class="parameter">$ident</code></span>
   , <span class="methodparam"><span class="type">int</span> <code class="parameter">$option</code></span>
   , <span class="methodparam"><span class="type">int</span> <code class="parameter">$facility</code></span>
   )</div>

  <p class="para rdfs-comment">
   <span class="function"><strong>openlog()</strong></span> opens a connection to the system
   logger for a program.  
  </p>
  <p class="para"> 
   The use of <span class="function"><strong>openlog()</strong></span> is optional. It
   will automatically be called by <span class="function"><a href="function.syslog.html" class="function">syslog()</a></span> if
   necessary, in which case <em><code class="parameter">ident</code></em> will default
   to <strong><code>FALSE</code></strong>.
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.openlog-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>

    
     <dt>
<em><code class="parameter">ident</code></em></dt>

     <dd>

      <p class="para">
       The string <em><code class="parameter">ident</code></em> is added to each message. 
      </p>
     </dd>

    
    
     <dt>
<em><code class="parameter">option</code></em></dt>

     <dd>

      <p class="para">
       The <em><code class="parameter">option</code></em> argument is used to indicate
       what logging options will be used when generating a log message.
       <table class="doctable table">
        <caption><strong><span class="function"><strong>openlog()</strong></span> Options</strong></caption>
        
         <thead>
          <tr>
           <th>Constant</th>
           <th>Description</th>
          </tr>

         </thead>

         <tbody class="tbody">
          <tr>
           <td><strong><code>LOG_CONS</code></strong></td>
           <td>
            if there is an error while sending data to the system logger,
            write directly to the system console
           </td>
          </tr>

          <tr>
           <td><strong><code>LOG_NDELAY</code></strong></td>
           <td>
            open the connection to the logger immediately
           </td>
          </tr>

          <tr>
           <td><strong><code>LOG_ODELAY</code></strong></td>
           <td>
            (default) delay opening the connection until the first
            message is logged
           </td>
          </tr>

          <tr>
           <td><strong><code>LOG_PERROR</code></strong></td>
           <td>print log message also to standard error</td>
          </tr>

          <tr>
           <td><strong><code>LOG_PID</code></strong></td>
           <td>include PID with each message</td>
          </tr>

         </tbody>
        
       </table>

       You can use one or more of this options. When using multiple options
       you need to <em>OR</em> them, i.e. to open the connection
       immediately, write to the console and include the PID in each message,
       you will use: <em>LOG_CONS | LOG_NDELAY | LOG_PID</em>
      </p>
     </dd>

    
    
     <dt>
<em><code class="parameter">facility</code></em></dt>

     <dd>

      <p class="para">
       The <em><code class="parameter">facility</code></em> argument is used to specify what
       type of program is logging the message. This allows you to specify
       (in your machine&#039;s syslog configuration) how messages coming from
       different facilities will be handled.
       <table class="doctable table">
        <caption><strong><span class="function"><strong>openlog()</strong></span> Facilities</strong></caption>
        
         <thead>
          <tr>
           <th>Constant</th>
           <th>Description</th>
          </tr>

         </thead>

         <tbody class="tbody">
          <tr>
           <td><strong><code>LOG_AUTH</code></strong></td>
           <td>
            security/authorization messages (use 
            <strong><code>LOG_AUTHPRIV</code></strong> instead
            in systems where that constant is defined)
           </td>
          </tr>

          <tr>
           <td><strong><code>LOG_AUTHPRIV</code></strong></td>
           <td>security/authorization messages (private)</td>
          </tr>

          <tr>
           <td><strong><code>LOG_CRON</code></strong></td>
           <td>clock daemon (cron and at)</td>
          </tr>

          <tr>
           <td><strong><code>LOG_DAEMON</code></strong></td>
           <td>other system daemons</td>
          </tr>

          <tr>
           <td><strong><code>LOG_KERN</code></strong></td>
           <td>kernel messages</td>
          </tr>

          <tr>
           <td><strong><code>LOG_LOCAL0</code></strong> ... <strong><code>LOG_LOCAL7</code></strong></td>
           <td>reserved for local use, these are not available in Windows</td>
          </tr>

          <tr>
           <td><strong><code>LOG_LPR</code></strong></td>
           <td>line printer subsystem</td>
          </tr>

          <tr>
           <td><strong><code>LOG_MAIL</code></strong></td>
           <td>mail subsystem</td>
          </tr>

          <tr>
           <td><strong><code>LOG_NEWS</code></strong></td>
           <td>USENET news subsystem</td>
          </tr>

          <tr>
           <td><strong><code>LOG_SYSLOG</code></strong></td>
           <td>messages generated internally by syslogd</td>
          </tr>

          <tr>
           <td><strong><code>LOG_USER</code></strong></td>
           <td>generic user-level messages</td>
          </tr>

          <tr>
           <td><strong><code>LOG_UUCP</code></strong></td>
           <td>UUCP subsystem</td>
          </tr>

         </tbody>
        
       </table>

      </p>
      <blockquote class="note"><p><strong class="note">Note</strong>: 
       <p class="para">
        <strong><code>LOG_USER</code></strong> is the only valid log type under Windows
        operating systems
       </p>
      </p></blockquote>
     </dd>

    
   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.openlog-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   成功时返回 <strong><code>TRUE</code></strong>， 或者在失败时返回 <strong><code>FALSE</code></strong>。
  </p>
 </div>


 <div class="refsect1 seealso" id="refsect1-function.openlog-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.syslog.html" class="function" rel="rdfs-seeAlso">syslog()</a> - Generate a system log message</span></li>
    <li class="member"><span class="function"><a href="function.closelog.html" class="function" rel="rdfs-seeAlso">closelog()</a> - Close connection to system logger</span></li>
   </ul>
  </p>
 </div>


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